The present invention relates to a device for the displacement of a shaft furnace probe which is introduced transversely into a furnace through a support block and a sealing packing; the support block and sealing packing being fixed to the furnace wall. The present invention comprises a frame disposed at the side of the furnace in the probe insertion axis and is provided with means for inserting and extracting the probe.
Shaft furnace probes, per se, are well known and are intended for measuring the temperature at different predetermined points inside the furnace; and for taking gaseous samples for analysis. The result of these measurements and analyses enables the operation of the furnace to be monitored and controlled. European Pat. No. 0 056 941 responding to U.S. Pat. No. 4,471,664, assigned to the assignee hereof, all of the contents of which are incorporated herein by reference, shows, for example, a probe of this type; and more particularly its support block fixed to the furnace wall.
In view of the fact that shaft furnaces, particularly blast furnaces, presently operate at increasingly high temperatures, a difficult problem arises in connection with the sealing packing, which must contain the furnace pressure not only during measurements but, above all, during the insertion and extraction of the probe. To this end, it is necessary to provide in the packing a plurality of juxtaposed sets of sealing rings. For the latter to ensure effective and durable sealing, it is necessary that during its movement, the probe should subject these sealing rings to little or no stressing, or to the least possible stressing, which means that the probe must, if possible, always be moved along the axis of the packing.
The probe is generally moved by means of devices known per se, such as pneumatic or hydraulic hammers, or by means of an endless traction chain mounted on a frame disposed opposite the insertion opening and in the axis of the latter. However, because of thermal expansion, the armouring of the furnace undergoes vertical displacements, so that both the insertion opening and packing can "rise" or "fall" relative to the probe movement mechanism. In addition, this device, which is mounted on the work floor fastened to the square tower around the furnace, may undergo vertical displacements due to slight movements of the square tower. As the result of these movements, the axis of the movement of the probe may differ from the axis of the packing, and this difference may become relatively great if the movements of the furnace wall and of the tower are in opposite directions. As mentioned above, however, if the axis of the movement of the probe does not coincide with the axis of the packing, the force required for the movement of the probe contains a vertical component which, if excessive, may damage the packing.